---
title: "SparseMultiply(_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/sparsemultiply(_:_:_:)-9kraw"
---

# SparseMultiply(_:_:_:)

Performs the multiply operation Y = AX_ _on a sparse matrix of single-precision, floating-point values.

## Declaration

```swift
func SparseMultiply(_ A: SparseMatrix_Float, _ X: DenseMatrix_Float, _ Y: DenseMatrix_Float)
```

## Parameters

- `A`: The sparse matrix A in Y = AX.
- `X`: The dense matrix X in Y = AX.
- `Y`: The dense matrix Y in Y = AX.

## Discussion

Discussion Use this function to multiply a sparse matrix by a dense matrix. The following equation is an example of a matrix-matrix multiplication where the first matrix is sparse:

Call SparseMultiply(_:_:_:) to calculate the result. let rowCount = Int32(4) let columnCount = Int32(4) let blockCount = 4 let blockSize = UInt8(1) let rowIndices: [Int32] = [0, 3, 0, 3] let columnIndices: [Int32] = [0, 0, 3, 3] let data: [Float] = [1.0, 4.0, 13.0, 16.0]

/// The _A_ in _Y=AX_. let A = SparseConvertFromCoordinate(rowCount, columnCount,                                     blockCount, blockSize,                                     SparseAttributes_t(),                                     rowIndices, columnIndices,                                     data) defer {     SparseCleanup(A) }

/// The values for _X_ in _Y=AX_. var xValues: [Float] = [10.0, -1.0, -1.0, 10.0,                         100.0, -1.0, -1.0, 100.0]

/// The values for _Y_ in _Y=AX_. let yValues = [Float](unsafeUninitializedCapacity: xValues.count) {     resultBuffer, count in          xValues.withUnsafeMutableBufferPointer { denseMatrixPtr in         /// The _X_ in _Y=AX_.         let X = DenseMatrix_Float(rowCount: 4,                                   columnCount: 2,                                   columnStride: 4,                                   attributes: SparseAttributes_t(),                                   data: denseMatrixPtr.baseAddress!)                  /// The _Y_ in _Y=AX_.         let Y = DenseMatrix_Float(rowCount: 4,                                   columnCount: 2,                                   columnStride: 4,                                   attributes: SparseAttributes_t(),                                   data: resultBuffer.baseAddress!)                  SparseMultiply(A, X, Y)     }          count = xValues.count }

## See Also

### Multiplication functions

- [SparseMultiply(_:_:_:)](accelerate/sparsemultiply(_:_:_:)-8d9lh.md)
- [SparseMultiply(_:_:_:_:)](accelerate/sparsemultiply(_:_:_:_:)-73ruq.md)
- [SparseMultiply(_:_:_:_:)](accelerate/sparsemultiply(_:_:_:_:)-2qh3a.md)